Quickly determine your Body Mass Index using feet, inches, and pounds. Accurate, instant, and private calculation designed for US units.
Enter your height and weight below for an immediate, private calculation.
In the United States, height is routinely recorded in feet and inches, and body weight is measured in pounds (lbs). Because the global definition of Body Mass Index is expressed as kilograms per meter squared (kg/m²), the US formula incorporates a mathematical scaling constant:
This formula produces the exact same clinical value as converting your weight to kilograms and height to meters before dividing.
Standard international adult reference ranges. Note that BMI is an epidemiological screening metric and should be evaluated alongside individual clinical indicators.
| Category | BMI Range (kg/m²) | Classification Status | General Health Assessment |
|---|---|---|---|
| Severe Thinness | < 16.0 | Underweight (Severe) | Elevated risk of nutrient deficiencies and low bone mineral density |
| Moderate Thinness | 16.0 – 16.9 | Underweight (Moderate) | Increased risk of nutritional compromise and fatigue |
| Mild Thinness | 17.0 – 18.4 | Underweight (Mild) | Mild risk; may be typical for some lean body types |
| Normal / Healthy Weight | 18.5 – 24.9 | Healthy Weight | Statistically lowest correlation with weight-related chronic conditions |
| Pre-Obesity / Overweight | 25.0 – 29.9 | Overweight | Slightly elevated cardiovascular and metabolic risk; evaluate body composition |
| Obesity Class I | 30.0 – 34.9 | Obesity (Class 1) | Moderate risk of hypertension, dyslipidemia, and type 2 diabetes |
| Obesity Class II | 35.0 – 39.9 | Obesity (Class 2) | Severe risk of cardiovascular complications and sleep apnea |
| Obesity Class III | ≥ 40.0 | Obesity (Class 3 / Severe) | Very severe health risk; comprehensive clinical management recommended |
Clinical context: These cutoffs apply to adults age 20 and older. Some health organizations (such as the WHO Asian expert consultation) suggest alternative cutoffs (such as overweight beginning at 23.0 and obesity at 27.5) for populations with differing body fat distributions.
Find clear, evidence-based answers to common questions about Body Mass Index calculation, accuracy, and interpretation.
Multiply your weight in pounds by 703, then divide that result by your total height in inches squared. For example, if you are 5'10" (70 inches) and weigh 150 lbs: (703 × 150) ÷ (70 × 70) = 105,450 ÷ 4,900 = 21.52 (Healthy Weight).